The present invention relates to a method of producing a metallic Si single crystal having low resistivity useful as a substrate for semiconductor devices such as LSI or super LSI.
Si has been used as a substrate material for semiconductor devices such as LSI or super LSI. An n-type semiconductor having electrons serving as a carrier is obtained by doping Si with an n-type dopant, while a p-type semiconductor having holes serving as a carrier is obtained by doping Si with a p-type dopant. Each semiconductor is fabricated to a semiconductor device bestowed with various properties designed for a specified use.
When a circuit is built up between fabricated semiconductor devices, a thin metal film such as Au or Al useful for wiring is vapor-deposited on a Si substrate. However, Si itself can not be used as for wiring due to great resistivity even in case of n-type or p-type Si.
Minute wiring can not be formed from the thin metal film. Besides, metal atoms diffused from the thin film to a semiconductor region cause a deep level, resulting in reduction of carriers by recombination. In short, the metal film puts restriction on integration of semiconductor devices with high density. On the other hand, a demand for provision of semiconductor devices good of performance but small in size becomes stronger and stronger in these days. Such the demand can not be attained by conventional methods due to the restriction.